How to deal with mocking?

I have been pondering the issue a it more and I realized there was something I forgot to mention. Just like how your sensitivity might have some small root in a vulnerability, his own humor might be coming from a defense mechanism against fear or lack of understanding. Something about your practice might bother him on some level he might not even recognize consciously, but it would still trigger his instinctive defensive measures.

Does he rely on humor when he is feeling stressed or out of place? or when he encounters situations that otherwise make him feel uncomfortable? if that's the case then it might be helpful to sit down with him in a friendly moment to ask him if there is anything about what you practice that worries or bothers him. The vitally important (and possibly tricky) part is being as neutral as you can be, and to demonstrate to him that you are open to hearing out his concerns without getting upset or feeling threatened by his thoughts.

It might bring to light some unexpected results, but if you two can get to the core of the issue, and get it out into the light, then you can also work together to address it.

Astraeues, there is absolutely no reason to insult people.

There is only one thing that will convince people who mock you (and your magic stick): results. Results are not the only alternatives, I know, but it's the only one with 100% certainty that convinces you of your seriousness. The same way a student who shit rules but never passes a qualifying examination... People do not take him seriously. Unlike mock preaching about magic, magick exists to bring results. So nothing better than using magic to bring solutions, with or without coven.
As an example, you mentioned the problem of flies, so it's a great alternative to using magic. And there are dozens of natural resources (formerly magic), currently turned herbal medicine, or "natural technology". Nothing better than using change of habits and customs under the aegis of "rituals" to your family reaping results. Note that this is not to preach any religion, but to use the nature that surrounds you to reap results with your (your) belief.
An alternative is to make an insecticide with 100 ml of DETERGENT, 100 ml of WATER, with 50 ml of VINEGAR (any one) and as an alternative 4 drops of the ESSENCE of your preference. Mix all this content and with the help of a funnel, place in a sprinkler.
Alone this does not solve anything, because to collect results you need to guide the staff to always apply their new "natural technology". Nothing better than putting together a "results coven" ...